McMinnville Water Department employees are conducting a water study late at night. The city is looking for water leaks that can only be found when no water is running.“We want residents to be aware we will be conducting this study,” said McMinnville Public Works director Bill Brock. “We don’t want to alarm anyone when they see the guys out late at night, but that’s the time we have to do this study.”Brock says the department will use a listening device to listen in on valves, meters, hydrants, etc. during times when no water is expected to be in use.“If there is any movement, we will be able to hear noise in the lines,” Brock said.